Photochromic Hydrophobic Eutectogel with High Adhesion, Stability, and Self‐Healing for Information Encryption, Underwater Wireless Communications, and Motion Monitoring

Abstract As an outstanding flexible conductive material, eutectogels have received increasing attention due to their potential applications in fields such as flexible wearable electronics and wireless communications. However, the development of multifunctional eutectogels with stability in underwater environments is still very challenging due to the high sensitivity of most deep eutectic solvents (DES) to water. Herein, a hydrophobic eutectogel is fabricated by simple photopolymerization, the introduction of macromolecular cross‐linking agents, fluorine‐rich monomers and dynamic light‐responsive functional ammonium molybdate tetrahydrate (Mo 7 ), as well as multiple dynamic interactions within the eutectogel, endowed it with excellent mechanical properties (160 kPa), long‐term underwater repetitive adhesion (102.99 kPa), underwater environmental tolerance (<5 wt.%), rapid self‐healing ability (>93%), sensitive and stable sensing capability (GF > 2.46) and reversible photochromic properties. Flexible wearable devices and underwater wireless communication systems based on hydrophobic eutectogels realized the applications of non‐contact information encryption, underwater wireless communication, and underwater real‐time motion monitoring. This work provides ideas for the development of multifunctional integrated photochromic hydrophobic eutectogels for information storage and encryption, underwater wireless communication, and intelligent monitoring.